Grate

ABSTRACT

A grate for supporting combustible material during burning having a cross member; legs mounted on the cross member adapted to support the member in elevated, horizontal position; and a plurality of air conduits mounted on the cross member and extended outwardly and downwardly therefrom so as to define a platform for the support of the material which is inclined toward the cross member; each conduit having an entrance remote from the member and an exit adjacent to the member so as to permit air heated by combustion to be drawn upwardly in convection currents through the conduits for discharge against the cross member to cool the grate and to improve combustion by establishing a flow of air about the material.

Unite States Patent 11 1 Simpson |4s| Sept. 4, 1973 GRATE [76] lnventor:Lee S. Simpson, 440 N. Cornelia,

{52] US. Cl. 126/121, 126/165 [51] Int. Cl. F2311 3/02 [58] Field ofSearch 126/121, 165

[56] References Cited UNITED STATES PATENTS 3,240,206 3/1966 Schutt126/121 1,640,771 8/1927 Hannum 126/121 2,453,954 11/1948 Wright 126/121X 3,001,521 9/1961 Reilly 126/165 X 3,635,211 1/1972 Englert 126/121Primary Examiner-William F. ODea Assistant Examiner-Peter D. FergusonAttorney-Herbert A. Huebner, Richard M. Worrel et a1.

[57] ABSTRACT A grate for supporting combustible material during burninghaving a cross member; legs mounted on the cross member adapted tosupport the member in elevated, horizontal position; and a plurality ofair conduits mounted on the cross member and extended outwardly anddownwardly therefrom so as to define a platform for the support of thematerial which is inclined toward the cross member; each conduit havingan entrance remote from the member and an exit adjacent to the member soas to permit air heated by combustion to be drawn upwardly in convectioncurrents through the conduits for discharge against the cross member tocool the grate and to improve combustion by establishing a flow of airabout the material.

1 Claim, 3 Drawing Figures GRATE BACKGROUND OF THE INVENTION The presentinvention relates to an improved grate and more particularly to such agrate which is intended for use in a conventional fireplace for improvedcombustion and radiant heating and for increased operational life of thegrate.

Conventional grates used in fireplaces, incinerators, and the like tosupport materials to be burned suffer from common deficiencies. Suchgrates are used in an intensely heated environment while supportingrelatively heavy loads. In order to withstand the heat, the grates arenormally constructed of solid metal bars which tend to deform under suchheat and load conditions. Similarly, continued heating and cooling ofthe grate causes the metal to become increasingly brittle. Consequently,after a relatively short period of time, the weight of the combustiblematerial deposited on the grate causes it to deform beyond a usefulshape and often to fracture so as to be useless.

Another problem frequently encountered with conventional grates is thatof an insufficient supply of oxygen during combustion. Depending uponthe design of the grate, the design of the fireplace or incinerator, andthe buildup of ashes, the circulated air is frequently insufficient tomaintain optimum combustion. This necessitates frequent rearranging ofthe combustible material, repositioning of the grate ancl removal of theashes under the grate in order to achieve proper burning. Further,conventional grates frequently are not sufficiently well designed topreclude the combustible material from falling forward off the grate.Thus, in the case of a fireplace, there is a significant danger that thefire be transmitted to adjacent areas. Similarly, in the case of afireplace, conventional grates make no provision for enhancing theproduction of heat by radiation and convection. Consequently, anexcessive amount of the heat produced from the fire is lost by upwardmovement through the chimney.

SUMMARY OF THE INVENTION It is therefore an object of the presentinvention to provide an improved grate which is resistant to intenseheat and heavy loads.

Another object is to provide such a grate which is self-cooling.

Another object is to provide such a grate which utilizes the naturalproperties of heated air so as to initiate circulation of air about thegrate for improved combustion of the material supported thereon.

Another object is to provide such a grate which has an inclined platformfor the support of combustible material in braced relation against theinner wall of the fireplace in which it is used so as to minimize thelikelihood of the material falling out of the fireplace.

Another object is to provide such a grate which has a cross memberadapted to emit radiant heat so as to improve the heatingcharacteristics of the fireplace.

A further object is to provide such a grate which motivates air heatedby combustion in convectional currents upwardly and outwardly from thefireplace so as to improve the heating characteristics of the fireplace.

A still further object is to provide such a grate which is of simple,utilitarian construction so as not to detract from the over-allappearance of the fireplace.

Further objects and advantages are to provide improved elements andarrangements thereof in a device for the purposes described which isdependable, economical, durable and fully effective in accomplishing itsintended purposes.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a transverse vertical sectionof a conventional fireplace showing the grate of the present inventionpositioned for use therein.

FIG. 2 is a somewhat enlarged perspective of the grate.

FIG. 3 is a somewhat further enlarged side elevation of the grate withportions thereof broken away to show the movement of heated airthere'through.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawing, FIG. 1 shows the grate of the present invention, generallyindicated by the numeral 10. The grate is preferably constructed of ametal such as low carbon steel. The grate is shown in FIG. 1 in positionin such a conventional fireplace 11 having a floor 12, an inner wall 13,and a mouth 14. Combustible material 15 such as logs are shownpositioned on the grate in FIG. 1.

The grate 10 has a tubular cross member 20 having opposite ends 21 and aperipheral surface 22. A pair of legs 23 are mounted, as by welding, onthe periphery surface of the member adjacent to the opposite endsthereof. The legs extend downwardly, normal to the member, so as tosupport the member in elevated, horizontal relation when the grate ispositioned on the floor 12 of the fireplace 11.

A plurality of tubular air conduits 30 each having an entrance end 31and an exit end 32 are mounted, as by welding, on the surface 22 of themember 20 in spaced, parallel relation between the opposite ends 21 ofthe member. The conduits extend righ't-angularly from the member so asto define an angle of some-what less than with respect to the legs 23.Each conduit is mounted on the member so as not to be flush with theperipheral surface thereof thereby defining a passage 33 between theexit end and the peripheral surface. Each of the passages opensdownwardly, as best shown in FIG. 3. The conduits extend from the memberin a common plane so as to define a platform 34.

OPERATION by conventional practice in order to start a fire. The

material is then ignited.

Upon combustion, the grate 10 operates automatically without adjustmentto perform its unique functions. The grate operates on thewell-recognized principle that air, when heated, expands and rises withrespect to relatively cooler air in the same vicinity. Thus, air withinthe conduits 30 is heated by conduction from the tire on the platform 34and consequently expands and moves in convectional currents upwardlythrough the inclined conduits. As can perhaps best be seen in FIG. 1,the air in the vicinity of the inner wall 13 of the fireplace 11 isdrawn in a vacuum effect into the entrance ends 31 of the conduits toreplace the air moving upwardly in the conduits. The intense heat ofcombustion occurring on the platform 34 causes the conduits themselvesto become intensely heated. Consequently, the already heated air passingthrough the conduits becomes even more heated by conduction during suchpassage and thereby expands to increase its velocity as travel continuesthrough the conduits. This heating of the air passing through theconduits correspondingly cools the conduits themselves by transportingthe heat with the moving air. Since this transmission of heat byconduction is continued as long as combustion continues, the conduitsare continually being cooled during such combustion. The result is thatthe conduits are maintained at a temperature below that which wouldotherwise be possible thereby greatly extending the operational life ofthe grate. Conventional grates are normally constructed of solid metalbars which, because of a lack of provision for internal cooling, readilydeform during continued use under the conditions of intense heat andheavy loads supported thereon. The grate of the present inventiontherefore remains structurally rigid for a significantly longer periodthan conventional grates.

Upon reaching the exit end 32 of the conduits 30, the now intenselyheated air is caused to be discharged from the conduits through thepassages 33. Because the passages face downwardly, the heated air isdischarged downwardly. Consequently, the air, because of its tendency torise, travels in both directions about the peripheral surface 22 of thecross member and eventually upwardly and outwardly in convectioncurrents through the mouth 14 of the fireplace for improved heating asbest shown in FIGS. 1 and 3.

The heating is further improved by passage of the intensely heated airabout the peripheral surface 22 of the cross member 20. Such passage, aswell as the proximity of the cross member to the point at whichcombustion is occurring, causes the cross member itself to becomeintensely heated. The positioning of the cross member adjacent to themouth 14 of the fireplace 11 thus further improves heating since thecross member itself emits radiant heat from its surface upwardly andoutwardly through the mouth of the fireplace.

The increase in the velocity of the air as it passes through theconduits 30 continues to draw more air through the entrance ends 31 ofthe conduits so as to create a continuous movement of air therethroughas long as combustion continues on the platform. Correspondingly,relatively cooler air is drawn in a vacuum effect from the mouth 14 ofthe fireplace 11 under the grate and through the spaces between theconduits so as to replace the heated air which is drawn through theconduits. Such cooler air contains a significantly higher percentage ofoxygen than the air removed during combustion and movement through thegrate thereby making possible improved combustion of the material 15 onthe platform.

Finally, the inclination of the platform 34 defined by the conduits 30serves securely to retain the combustible material 15 thereon and topreclude its falling off the grate l0. Ordinarily, the combustiblematerial is supported on the platform, as shown in FIG. 1, in bracedrelation against the inner wall 13 of the fireplace 11. It should alsobe noted that the simple, utilitarian construction of the grate insuresthat it does not detract from the individually aesthetic qualities ofthe fireplace in which it is used.

The present invention therefore provides a grate having an extremelylong operational life, improved characteristics of combustion, improvedcharacteristics of heating by radiation and convection, and improvedcharacteristics of safety.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the illustrative detailsdisclosed.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A grate for use in the burning of logs in an open fireplace,comprising:

A. a cross member of -a cylindrical configuration formed of aheat-conducting material;

B. means including a plurality of similarly configured, verticallyoriented legs fixed to said cross member adapted to support said crossmember above the plane of a floor of a selected open fireplace, withinthe opening thereof and at the interface of a heated body of atmosphereand a body of atmosphere to be heated;

C. a plurality of elongated tubular members for supporting logs in aburning state arranged in coplanar relation, each said tubular memberbeing suspended at one end thereof from said cross member, and disposedat a downward inclination with respect to said cross member;

D. means defining within the uppermost end of each of said elongatedmembers a discharge opening disposed in juxtaposition with the externalsurface of said cross member for discharging heated air at saidinterface; and

E. means defining within the lowermost end of each of said elongatedmembers an intake opening for receiving air from said heated body ofatmosphere, whereby the elongated members are cooled as air is drawnthrough the intake openings of said elongated tubular members, furtherheated within the tubular members, as heat is transferred thereto, andfinally discharged from the uppermost ends of said tubular members atsaid interface bodies of atmosphere.

a: a: a a a:

1. A grate for use in the burning of logs in an open fireplace,comprising: A. a cross member of a cylindrical configuration formed of aheat-conducting material; B. means including a plurality of similarlyconfigured, vertically oriented legs fixed to said cross member adaptedto support said cross member above the plane of a floor of a selectedopen fireplace, within the opening thereof and at the interface of aheated body of atmosphere and a body of atmosphere to be heated; C. aplurality of elongated tubular members for supporting logs in a burningstate arranged in coplanar relation, each said tubular member beingsuspended at one end thereof from said cross member, and disposed at adownward inclination with respect to said cross member; D. meansdefining within the uppermost end of each of said elongated members adischarge opening disposed in juxtaposition with the external surface ofsaid cross member for discharging heated air at said interface; and E.means defining within the lowermost end of each of said elongatedmembers an intake opening for receiving air from said heated body ofatmosphere, whereby the elongated members are cooled as air is drawnthrough the intake openings of said elongated tubular members, furtherheated within the tubular members, as heat is transferred thereto, andfinally discharged from the uppermost ends of said tubular members atsaid interface bodies of atmosphere.